Effects of glucose, pyruvate, lactate, and amino acids on muscle protein synthesis.
Effects of glucose, pyruvate, lactate, and amino acids on muscle protein synthesis.
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葡萄糖、丙酮酸、乳酸和氨基酸对肌肉蛋白质合成的影响。
DOI：
10.1152/ajpendo.1982.242.3.e184
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发表时间：
1982
期刊：
影响因子：
--
通讯作者：
Buse,MG
中科院分区：
文献类型：
--
作者：
Hedden,MP;Buse,MG
蛋白质合成测定大鼠膈肌孵育血清氨基酸+ 0.35 mM L-[2，6 - 3 H]酪氨酸和不同的能量产生底物。与5.5 mM葡萄糖（含或不含放线菌素D）孵育的肌肉比与11 mM丙酮酸或11 mM乳酸孵育的肌肉合成更多的蛋白质。组织ATP与乳酸孵育期间下降，但丙酮酸维持ATP，ADP，磷酸肌酸以及葡萄糖。在无葡萄糖培养基中培养的肌肉中葡萄糖6-磷酸减少。从底物产生的14 CO2是[1- 14 C]丙酮酸盐大于[1- 14 C]乳酸盐大于[3，4 - 14 C]葡萄糖。测量细胞内乳酸/丙酮酸以评估细胞质游离NADH/NAD+;不同培养基对这些比率的影响为乳酸大于葡萄糖=乳酸+丙酮酸大于丙酮酸+葡萄糖大于丙酮酸。乳酸盐+丙酮酸盐（8.8 + 2.2mM）比丙酮酸盐以及葡萄糖更好地支持蛋白质合成。将葡萄糖添加到丙酮酸盐中加速蛋白质合成并增加NADH/NAD+。碘乙酸盐（0.1 mM）抑制糖酵解NAD还原，并在丙酮酸盐存在下消除葡萄糖对蛋白质合成的刺激作用。补充丙酮酸培养基与1 mM亮氨酸或异亮氨酸刺激蛋白质合成，但β-羟基丁酸，苹果酸，α-酮异己酸，和所有其他氨基酸是无效的。细胞质氧化还原电位可能作为骨骼肌蛋白质合成的翻译调节剂。
Protein synthesis was measured in rat diaphragms incubated with serum amino acids + 0.35 mM L-[2,6-3H]tyrosine and different energy-yielding substrates. Muscles incubated with 5.5 mM glucose (with or without actinomycin D) synthesized more protein than those incubated with 11 mM pyruvate or 11 mM lactate. Tissue ATP decreased during incubation with lactate, but pyruvate maintained ATP, ADP, and creatine phosphate as well as glucose. Glucose 6-phosphate decreased in muscles incubated in glucose-free media. 14CO2 production from substrates was [1-14C]pyruvate greater than [1-14C]lactate greater than [3,4-14C]glucose. Intracellular lactate/pyruvate was measured to assess cytoplasmic free NADH/NAD+; the effect of different media on these ratios was lactate greater than glucose = lactate + pyruvate greater than pyruvate + glucose greater than pyruvate. Lactate + pyruvate (8.8 + 2.2 mM) supported protein synthesis better than pyruvate and as well as glucose. Adding glucose to pyruvate accelerated protein synthesis and increased NADH/NAD+. Iodoacetate (0.1 mM) inhibited glycolytic NAD reduction and abolished the stimulatory effect of glucose on protein synthesis in the presence of pyruvate. Supplementation of pyruvate media with 1 mM leucine or isoleucine stimulated protein synthesis, but beta-hydroxybutyrate, malate, alpha-ketoisocaproate, and all other amino acids were ineffective. The cytoplasmic redox potential may act as a translational modulator of protein synthesis in skeletal muscle.